In a wind power generation device according to the background art of the present application, upon receiving wind power, blades rotate the main spindle connected thereto, and a speed-up gear increases the rotation of the main spindle, thereby driving a power generator.
However, in the above-mentioned wind power generation device, the rotation speed of the main spindle changes due to the change in wind speed or wind direction, whereby the wind power generation device has a disadvantage that the rotation torque of the main spindle to be input from the speed-up gear to the power generator changes and the power generation efficiency of the generation device lowers. Hence, in the wind power generation device, there is a need for a technology for suppressing the change in the rotation torque and improving the power generation efficiency.
Furthermore, the wind power generation device is installed on the assumption that the generation device is usually used for a long time, 10 or more years. Moreover, the wind power generation device is installed, for example, in mountainous or coastal areas or at sea due to noise caused by the rotation of the main spindle and the driving of the power generator, wind conditions, etc. In addition, since the main components of the wind power generation device are required to be installed at a high place, such as a wind power generation tower, and the components themselves are large and heavy, a great amount of labor is required for installing and removing the components at the time of maintenance. Hence, it is desired that maintenance is required as less as possible, and there is a need for a wind power generation device with a long life and high reliability.
On the other hand, in order that a synchronous power generator is operated in parallel in an operation state synchronized with a power generator in another system, it is proposed to provide a one-way clutch between the output shaft of the speed-up gear of the synchronous power generator and the drive shaft of the power generator (refer to Patent Document 1, for example).